关键词: 时变衰落, 线性调频, 最小描述长度, Wigner－Hough变换, 正交频分复用

Abstract: The wireless channel with time-varying distortion deteriorates the performance of communication systems seriously.So the parameters of time-varying channel have to be estimated exactly for the best design of system and equalization in the receiver.This paper proposes an algorithm to estimate the parameters of time-varying channel based on Wigner－Hough Transform（WHT） and parametric channel model，with a single-component Linear-Frequency Modulated （LFM） signal inserted into the symbols sending to detect the channel in the Orthogonal Frequency-Division Multiplexing （OFDM） system.In the algorithm，we employ the Minimum Description Length（MDL） criterion to detect the number of paths in the channel.Then WHT and FFT can detect and estimate the parameters of time-varying channel from the received pilot signals.The simulation results show that the proposed algorithm exhibits good performances.

Key words: time-varying distortion, LFM, MDL criterion, WHT, OFDM